The present invention relates to a golf club head having a hollow structure composed of at least three parts having different specific gravities.
As well known in the art, to increase the lateral moment of inertia of a golf club head is advantageous to decreasing of variations of golf ball flying directions and traveling distances. Therefore, in order to increase the lateral moment of inertia of the golf club heads, golf club manufacturers have hitherto devoted their efforts to increasing of the head volume.
Recently, however, Golf Rules limit the maximum volume of the golf club heads. As a result, the previous technique to increase the head volume is no longer useful. It is necessary to establish a new way to increase the moment of inertia with the limited head volume.